Securing disposal flange on new stainless sink

[OklahomaDave]

Greetings!

I have just completed the reinstallation of a garbage disposal into a new stainless sink in our kitchen, and while the install appears to have been successful, I am concerned about one thing.

The previous sink into which this disposal was installed was essentially flat on the bottom, and the disposal mounting flange connected flush against it. The new sink however, has very slight angles toward the drain, and thus is not similarly flat on the bottom. As a result, the flange does not (and cannot) be secured flat against the bottom of the sink . When I attempted to use the disposal wrench to lock the the appliance into the ring, the entire assembly including the flange started to rotate, implying the flange wasn't tight enough - but I was afraid I'd already tightened the screws as much or more than was possible without risking damage to either the flange or the sink! Arrggh!!! I finished the rest of the connection/installation, and it isn't leaking...but....it obviously isn't as secure as it should be!!

So, now...my concern is that when I start using the disposal, the torque of the motor will eventually cause that disposal to try and rotate in place slightly, possibly loosening the plumber's putty used to seal the top mounting flange to the sink and creating a leak. I was concerned about trying to tighten the screws on the bottom of the flange excessively and risk damaging/bending the sink itself or squeezing out too much of the putty on the top of the flange and inducing a leak.

Are there some special considerations regarding using these standardized ring-lock flanges on stainless sinks that I'm overlooking or otherwise unaware of? Right now, the disposal is in place and working, but I'm not entirely confident it is as secure as it should be. Thought I might solicit opinions from the good folks here about what, if anything, I should try next - including just leaving it alone and seeing what happens as we start to use it.

Thanks again.

 

[Dj2]

A GD, no matter the brand, should not rotate. Fasten it from under the sink, maybe you can get a helper to hold it tight from the sink side while you tightening.

Also, did you read the instructions? for a SS sink you may have to use the rubber gasket provided in the kit instead of plumber's putty.

 

[Sponsor]

 

[OklahomaDave]

A GD, no matter the brand, should not rotate. Fasten it from under the sink, maybe you can get a helper to hold it tight from the sink side while you tightening.

Also, did you read the instructions? for a SS sink you may have to use the rubber gasket provided in the kit instead of plumber's putty.

Yes, I did read the instructions from the disposal mfr - in fact, downloaded the most current for my model before installing - and they explicitly said to use plumber's putty. That was consistent with the fact that there was no rubber gasket in the kit - only the "fiber" one that goes under the sink. There were no special caveats for stainless sinks. The install matches the installation instructions.

 

[Dj2]

What brand and model is it?

 

[OklahomaDave]

KitchenAid Kadette 250

 

[Dj2]

I believe your GD has 3 screws for tightening. Use a screwdriver to tighten from down under (get inside the cabinet face up) after you positioned the GD in the desired angle, till the unit cannot be rotated. A flashlight will help.
If you're still having issues, maybe it's time to call in a pro.

 

[OklahomaDave]

Thanks, dj2, but I think I've not done a very good job of describing my situation. My apologies.

The unit is already installed. I installed the mounting flange per the instructions, which I had done previously when I replaced this unit under our previous sink a few months ago, so I was not entirely unfamiliar with the process. I had a *specific* concern about the installation of the unit against a new sink, one wherein there was less physical contact between the flange surface and the bottom of the sink, thus less reliance on friction to inhibit rotation. In that vein, I was concerned specifically about *overtightening* those three screws to the point of either damaging the flange or the sink. I thought perhaps there were special considerations regarding stainless steel sinks of which I was not aware. I've not found any such issues in other research

I'm certainly no stranger to living in the cabinet on my back. I've spent the better part of a day replubming the drain from this disposal and rebuilding a loop vent to accommodate a new sink, so I've certainly spent plenty of time under that cabinet, cementing fittings, and inserting a flex coupling where I no longer had room to insert a new cemented fitting. The last part of all this was to restore the disposal - and as you'd rightly suggested, I've tightened each of the three screws on the flange to just-beyond hand tight, squeezing out some of the putty from the top of the flange.

I re-inspected the mount this afternoon, checked all three screws, and now none offer any movement beyond the hand-tight level I'd applied. I also used the wrench once again to secure the lock collar to the flange, and it did not cause the unit to rotate as a whole. I'll test the unit tonight and see if the issue is resolved.

 

[Terry]

With stainless, I use very little putty. When it's tightened down, putty will come out. I sometimes wait about thirty seconds and then retighten, allowing a bit more putty to escape on it's own. If there is excess putty below the sink, I remove that too before I start assembling the parts.
It should lock into place past the notch.

 

[OklahomaDave]

Thanks, Terry

After re-checking the unit tonight, and running some actual food debris through it, and seeing no leaks, movement, or weakness, I'm declaring it good until and unless we have a problem. Not going to borrow any more trouble.

Thanks everyone.

-David